Imaging systems based on light waves are becoming more widely used for object detection as semiconductor processes have become faster to support such systems. Some imaging systems are capable of providing dozens of images per second, making such systems useful for object detection and/or tracking in changing environments. Due to their potentially small form factor and potentially high signal fidelity, some imaging systems are well suited for application in many types of vehicles (cars, busses, trains, etc.). Additionally, some imaging systems are well suited for gesture control, or the like, in many types of consumer devices (e.g., television, computers, tablets, smartphones, etc.). While the resolution of such imaging systems may vary, applications using these systems are able to take advantage of the speed of their operation.
Time-of-flight cameras, for example, may use pixels to measure the time-of-flight of a light signal as it travels between the camera and an object, to determine a distance of the object from the camera. Multiple pixels may also be used, where light signals associated with individual pixels may provide distance measurements for discrete points on the object, forming a three-dimensional “distance image.” This can be made possible by detecting differences in the delays associated with reflected light signals off of the discrete points, for example.
Time-of-flight principles can be sensitive to delays occurring inside the camera, however, as the delays can distort the distance measurements. In some cases, the driver of the illumination unit, which emits the light radiation, can cause additional delays. For example, delays can occur between the electrical illumination control signals generated by the system and the actual emitted optical signals. Since delays can be temperature dependent, or vary based on other factors, compensating for the delays can be problematic.